Marshall mcdonald



(No Model.) Y K Y M. MGDONALD.

FILTER.

No. 455,573. Patented July 7, 1891.l

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UNITED STATES PATENT OFFICE MARSHALL MCDONALD, or WASHINGTON, DISTRICTOE COLUMBIA, AssIeNoR To THE AUTOMATIC FILTER COMPANY, or SAME PLACE.

SPECIFICATION forming part of Letters Patent No. 455,573, datedd'uly 7,1891.

' Application filed May 20, 1890. Serial No. 352,573. (No model.) l a Toall `whom t may concern.'

Be it known that I, MARSHALL MCDONALD,

of Vashington city, in the District of Colun bia, have invented a newand useful Improvement in Filters, of which the following isaspecification. My invention relates -to certain improvements in the'filter shown and described in my Letters Patent, No. 381,406, datedApril Io 17, 1888. In said filter there is an outward case, a porousfiltering medium, certain channels and a body of sand, and means wherebyparticles of sand are carried upward by a current or currents of waterin contact with part of the filtering-surface, and are discharged intoother channels and carried downward in a body over other portions of`the filtering-surface. It has been found that this method of operationwill not maintain 2o the filtering-surface free from the slimy depositsthat obstruct the filtering action, and

I therefore make use of a practically -solid body of sand, movingdownward over the entire filtering-surface, as set forth and claimed inmy application for Letters Patent, Serial No. 352,573, in connectionwith certain in1- proved mechanical features hereinafter described, andillustrated in the accom pan ying drawings, in Which- Figure l is avertical section of a filter embodying my improvement; Fig. 2, ahorizontal section on the line A A, Fig. l.

C is the outer face of the filter, which is preferably made of glass inthe form of a cylinder, the transparent case permitting the operationswithin to be observed. This cylinder is clamped tightly between twometallic heads B B', connected and drawn together by means of tie -rodsB2, passing through iianges ot' the edge and provided with nuts. Insteadof rods a screw -joint may be used between each head and the cylindersimilar to that employed on fruit-jars. In any case the joint is madetight by the use of a suitable packing or gasket.

other support, it is provided with a base D, and there is an outlet-pipea at the top and an inlet-pipe a' at the bottom, the former comlVhen thefilter is to rest upon a table or municat-ing with the pipe b, leadingto the service-pipe of the house, and the latter with the inlet-pipe b',connecting with the watermain, the two pipes I? b being connected by apipeV E, having au intermediate stop-cock c, and there is another smallstop-cock C in the pipe b. By opening the cock o and closing the cockC:water .may pass through :the service-pipe without circulating throughthe filter. By closing the cock c and openingthe cock c all of the Watermay be caused to circulate'through the `filter, while by partiallyopening'both cocks the water may be divided between the filter and theservice-pipe, and thereby the-force of water-current for lifting andcirculating the sand, as set forth hereinafter, may be regulated andadjusted in accoi-dance with the pressure and location.

-The lower head B has sides inclining toward an upwardly-projectingnozzle surmounted by a detlecting-cap e, whereby the body of sand in thecasing is thrown toward the nozzle, While a `guard or diaphragm GT,which is iiariug or in the form of a cone and provided with passages orperforations d, serves to limit the iiowV of the sand toward the nozzle,and also serves as a support for a central tube F, the lower end ofwhich is above the n deiiecting-cap. Above the tube F is a deflector F',whichserves to distribute the upfiowing current radially and uniformlyas it passes from the tube F. l

Suitably supported within the casing, and as shown by the tube F, is aring or spider H,

from which hangs the filtering medium, as

shown in the form of tubes I, which are free at their lower ends andsimply suspended from the spider at the upper ends, so that each may befitted in its place without accommodating it to the dimensions of theother. 'lhere may be any suitable number of tubessix being shown, andeach' lconsists of a cylinder of porous earihenware or othermaterial andupper metallic cap Orheadf, a lower capor head g, and the chamber thusinclosed communicates with the outlet-pipeof the lfilter. Thus each headf has an outlet-port communicating with an annular chamber in the spideror ring H, and the latter chamber communicates with an outlet-pipe K,extending through the head B of the filter. The heads f g are suitablyconnected with the tubesfor instance, the upper head f is formed with aneXteriorly screw-threaded hollow coupling f', screwing into the bottomof the ring H and inner threaded hollow coupling f2, with openings f3communicating with the interior or chamber of the tube. Into the end ofthe coupling f2 screws the end of a tie-rod J, which extends through thebottom head t, with a head or nut at the lower' end, and, if necessary,a gasket to pack the joint.

The pipe K preferably extends to a reservoir, either at a high altitudeor with an aircushion, whereby when the-inlet-valve C is open and theservice-pipe .is also opened to permit the water to flow through thefilter, thereby reducing the pressure therein, there will be aback-pressure from the inside of the filter-tubes, causing the filteredwater to flow outward and aid in cleansing said tubes. Vhen theservice-pipe is closed and the water can enter only through the pipe b',the pressure Within the'filter is greater than in the tube and the waterfiows inward through the latter and is filtered.

L is a funnel or hopper communicating with an opening in the upper capD, provided with a stop-cock and serving to facilitate the introductionof sand into the casing C, such quantity being introduced as will form asolid body surrounding all of the filtering-tubes nearly to the upperends of the latter.

It will be noted that the pipe F forms a channel through which thecurrent carrying lthe particles of sand flows upward without contactwith the filtering-surface, so that the body of sand lies in a solidmass around the filtering-tubes.

When the outlet for the filtered water is opened, the pressure withinthe ltering-tube is reduced, the water flows through the latter and iscleansed; but when the outlet to the service-pipe isopened the sand andwater iiow upward through the tube F and are then deflected by thedeflector F, the particles of sand to be deposited upon the mass belowwhile the water flows through the servicepipe. While the particles ofsand carried upward through the tube F move rapidly the body of sandaround the filtering-tubes settles gradually with the particles incontact with each other and with the tubes abrading the sides of thelatter, grinding off all adhering impurities by a species of glacialaction at the time when the back-pressure from the tubes aids inloosening the impurities.

It willbe seen that the single channel F serves as a means of elevatingthe particles of sand that are distributed uniformly and evenly around alarge number of tubes,where by the filtering capacity of the filter isvery great'and may be increased by the simple addition of other tubeswithout any other change in the construction ot' the other operatingparts of the filter.

Without claiming the use of a body of sand carried solidly over thefiltering medium and the creating of a back-pressure during thismovement of the sand, which is set forth in a separate application,Serial No. 377,089; nor the features set forth and claimed in a separateapplication No. 352,573, and without limiting myself to the preciseconstruction and operation of parts shown, I claiml. The combination,with an outer case having two heads and means for connecting themtogether, and an inlet-pipe at the lower end, of a central tube orpassage-way F, opening at both top and bottom into the outer case, aseries of porous filtering-tubes I, and a hollow ring communicating withthe interior of the same and having an outlet, substantially as shownand described.

2. The combination, with the cylindrical case C, of an 'upper head B, alower head B', inlet-pipe a', conical perforated diaphragm G, a centraltube F, supported thereupon, and a hollow ring H, supported upon the topof the tube F and having pendentporous filtering-tubes I, substantiallyas shown and described.

3. The combination of the porous tube I, the hollow ring H, the head ofscrew-couplings f and f2, holes f3, the lower head g, and the centralrod f, passing from screwcouplings f2 through the lower head andconnectin g the two heads to the porous tube, substantially asdescribed.

4. The combination of the case for receiving the water to be filtered, achannel for the upward flow of a water-current, a nozzle below saidchannel, a filtering medium consisting of a series of filtering-tubesarranged around the channel, and means for suspending the tubes below asupport therefor in said case, substantially as set forth.

5. The combination of the case provided4 with a channel for the upwardflow of a current of water and with a body of sand around said channel,and a series of filtering-tubes arranged around said channel, containingchambers communicating with an outlet-pipe for the filtered water,substantially as set forth.

G. The combination, with a case containing a body of sand, of awater-jet, a tube arranged above said water-jet in said case, a seriesof filtering-tubes supported by the tube F, and a deiiector arranged todeflect laterally the current rising through the tube F, substantiallyas set forth.

7. The combination of the case, central tube F and water-inlet nozzlebeneath said tube, a series of filtering-tubes surrounding the tube F,and a body of sand between the case and the tube F and surrounding thefilteringtubes in direct contact therewith, substantially as set forth.

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8. The combination of the ease for reeeiv- Wit-h openings surroundingthe nozzle to reguing the water to be lcered,l a channel for late the owof sand thereto, substantiallyas the upward 'low of a Water-current, anozzle set forth. below said channel, :L lterng medium ar- 5 rangedwithin the easing, a body of sand sur- I YVtnesSes:

rounding the said filtering medium in direct EDW. W. BYRN, Contact withthe surface thereof, and a guard l MARSHALL MQDONALD.

SoLoN C. KEMON.

